Extraterritorial legislation is a body of laws that makes it possible to prosecute one country's citizens for crimes they commit in another country. Such laws enable governments, for example, to bring sex tourists who abuse children in another country to trial.

Some countries - including among others Japan, Netherlands, Norway, Sweden and Switzerland - apply extraterritorial jurisdiction to offences committed by their nationals abroad as a general principle. There are no special provisions to deal with crimes connected with child sex tourism.

Countries such as Belgium, France and Germany have adjusted their extraterritorial jurisdiction legislation to make it easier to prosecute a case where children are the victims. The Netherlands, for example, does not require a complaint by the victim or the foreign government to be made; Dutch prosecutors can pursue a case on their own initiative.

Some countries have legislated specifically for crimes of child sex tourism, most notably Australia, where the Crimes (Child Sex Tourism) Amendment Act of 1994 extended the existing extraterritorial jurisdiction to offences against children committed abroad.

Differences in language, culture and police and legal systems make extraterritorial jurisdiction difficult to apply in practice. Although a crime took place in country 'A', the evidence has to be gathered by the police of country 'B' where the trial will take place. Criminal evidence must be obtained and preserved under very strict conditions for the burden of proof to be discharged in court, so the police can encounter many difficulties.